Wireless communication networks are limited, with respect to range and coverage, by deterioration of signals to unacceptably weak levels. Indiscriminately boosting or amplifying signals by individual subscribers, however, causes interference that can render large portions of the network useless. Such interference causes harm to both the subscriber and the service provider. The subscriber loses the service that he or she originally hoped to enhance by signal boosting. The service provider loses revenue from unrealized connections and eventually from lost subscribers dissatisfied with poor service. What is needed is a communications booster that is sufficiently “smart” and foolproof to know when and where to amplify or not to amplify.
In particular, a smart communications booster must be able to sense where it is located with respect to base stations. For example, if it is too close to a base station, then it can cause overwhelming interference to the base station with an unnecessarily amplified signal. To prevent such interference, the smart booster must have continuous access to a map so that it can compare its location with the known locations of base stations. A memory card, which is an essential part of this invention, is the ideal way to provide a map. Further, such memory cards are removable so that they can be revised or replaced as the locations of base stations, and other attributes of the communications infrastructure, change over time.
Methods presently exist to compensate primarily for the deterioration of signals, with little or no attention to the interference those methods may cause. In the case of cellular and PCS communications networks, for example, four such methods are: 1) bi-directional amplifiers, or BDAs; 2) additional cell sites; 3) femtocells; and 4) private subscriber high gain antennas. Bi-directional amplifiers boost both uplink and downlink signals, without regard to signal strength. Additional base stations can provide service at locations where coverage was not previously available. Femtocells extend coverage into small regions such as home interiors by transferring the wireless link to the internet. Individual subscribers can attach special purpose antennas to their transceivers that provide signal gain. All of these approaches, however, have significant disadvantages.
Bi-directional amplifiers, or BDAs, boost both uplink and downlink signals whether the subscriber is located far away from or in close proximity to a base station. In the latter case, the boosted uplink signal overwhelms the base station, rendering it effectively inoperative. The interfering signal may exceed that allowed by FCC regulations. Countless connections are dropped or never completed so long as the subscriber remains in close proximity. BDAs cannot sense their locations with respect to base stations. BDAs are completely uncontrolled by service providers, leaving those providers unprotected. They cannot be remotely controlled so that an adversely affected base station might switch them off. It follows that BDAs cause substantial loss of revenue to service providers.
Additional cell sites are not practical in many cases, especially at the very locations where they might do the most good. In marginal areas with few subscribers, the capital expenditure for a complete base station cannot be justified. In residential areas, restrictive zoning and public opposition, prevent the construction of new base stations.
Femtocells are by design limited to locations that can provide internet access. So, except within the confines of a small region, such as a home interior, they are not suitable for mobile use. They are certainly not suitable for wide ranging mobile stations.
Customized antennas for individual subscribers are generally not practical. They are by definition expensive compared with mass produced antennas. They require specialized engineering knowledge by the subscriber. Generally, they are large and must be carefully oriented so that they are not suitable for mobile stations. Again because of size or elevation on a tall tower, they may be prohibited by zoning restrictions.